It's an invention that will send a shiver down the spines of pirates everywhere.

A new type of laser weapon effective against moving targets more than a mile away is being developed by British scientists.

Defence company BAE Systems has come up with the non-lethal device in response to the increasing number of commercial, and private, vessels hijacked by pirates off the coast of Somalia.

The laser works by enshrouding the ship using it in a green shroud that leaves the pirates unable to steer a direct course or aim their weapons accurately.

The device, which works in daylight and at night, has been subjected to trials at the Pershore Lasers Trials Range in Worcestershire.

Roy Clarke, spokesman for BAE Systems Advanced Technology Centre, said: 'We are using the laser as a kind of dummy sun that we can hide the vessel behind.

'As you go up in power with a laser, you get to a point looking at it creates a big bright light that dominates everything in your field of view.'

The laser works by emitting a concentrated blast of green light that temporarily dazzles anyone who looks at it.
The result is to completely disorientate pirates, leaving them unable to find, let alone board, a target vessel.

BAE Systems' new anti-piracy department has been developing the weapon in conjunction with a high frequency radar that can locate the small boats commonly used by Somali pirates.

The radar then directs the laser towards the approaching boat.

It is, however, harmless and does not damage the eyesight of anyone looking at it, should the laser dazzle an innocent craft.

Bryan Hore, the head of the BAE Systems anti-piracy department, told the Daily Telegraph: 'We have started to look at the piracy issue over the past 18 months due to the increasing threats to vessels around the Gulf of Aden and the Arabian Sea.

'The laser provides a secondary capability over larger distances as it can act like a warning.

'Pirates approaching a vessel rely on the element of surprise, so by detecting those vessels and directing a laser onto them more than a kilometre away, it provides a clear signal to them.

'As the pirates come closer to about 400 or 500 metres of the ship, the power of the laser can be increased so that it affects their concentration and distracts them.

'We are also going to look at how different patterns and flickering can increase that affect.'